JP2610592B2 - Container with static crushing agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container containing a static crushing agent used for pile head treatment of cast-in-place piles.

[0002]

2. Description of the Related Art In general, as a foundation pile for building a building, a bridge or the like, a pile hole is excavated at the site at the site, and ready-mixed concrete is poured into the pile hole to form a pile. Pile is used. In this case,
It is necessary to crush and remove the defective concrete at the pile head prosperity. However, in the conventional crushing method using a breaker or the like, noise and vibration applied to the neighborhood cause deterioration of the environment, which is a problem.

[0003] In order to solve such a problem, the present applicant has already proposed a pile head treatment method using a static crushing agent (Japanese Patent Application No. 57-201048). In this pile head treatment method, for example, a steel cage with an empty spiral sheath tube attached is laid in the excavated pile hole, and a static crushing agent kneaded with water is filled in the spiral sheath tube before placing concrete, Hydraulic expansion of the static crushing agent was attempted along with curing of the concrete, and cracks were generated on the cutting line of the concrete pile to remove defective concrete in the excess portion.

[0004]

However, in the above-mentioned conventional pile head treatment method for cast-in-place piles, water is added to a static crushing agent, kneaded in advance to form a slurry, and then the sheath tube is filled. Although the crushing effect is excellent because of the use method used, there is a problem that the work is complicated, such as the measurement of the kneading water of the static crushing agent, the kneading work, and the adjustment of the inflation pressure expression time after kneading. There was a point. In addition, when the pile head of the cast-in-place pile is treated using a static crushing agent, only a crack of about several mm can be generated, which is insufficient for the removal treatment of the pile head excess portion. However, there is a problem in that post-processing takes a long time.

[0005] Therefore, a technical problem in the present invention for solving the above-mentioned problems is to avoid the complexity of the static crushing agent filling operation in the cast-in-place operation and to facilitate the post-processing of the container containing the static crushing agent. Is to provide.

[0006]

According to the present invention, as a specific means for solving the above problems, a container containing a static crushing agent has a particle size of 1 to 2 mm of 15 to 20% by weight and a particle size of 2 to 4 m.
m is 55 to 60% by weight, and a particle having a particle size distribution of 35 to 20% by weight having a particle size of 4 to 5 mm is filled with a static crushing agent granulated, and a cylindrical impervious material having both ends opened. It is a container.

[Concrete Configuration] The static crushing agent used in the present invention comprises calcium alumino ferrite [(CaO) ₄ .Al ₂ O ₃ .Fe ₂ O ₃ ], free calcium oxide (CaO) and oxidized Magnesium (Mg
O) as a basic component, to which a borate or the like is added as a retarder. Then, by appropriately changing the type and amount of the retarder, the onset time of the hydration expansion pressure can be adjusted.

[0008] The reason why the static crushing agent is formed into granules is to maintain a space between the particles so that the stabilizing solution can sufficiently wrap the particles. Thereby, even if the container filled with the static crushing agent is simply immersed in the stabilizing solution, each granule hydrates sufficiently and develops an expansion pressure. Means for forming the static crushing agent into granules include a method in which a dry powder of the crushing agent is continuously granulated at a high pressure into a strong almond-like briquette by a briquetting machine, or a crushing method by a compacting machine. A method in which a dry powder of the agent is compression-molded into a plate shape using a smooth roll, and then crushed and granulated, and other dry compression molding methods are exemplified.

The size of the granules of the static crushing agent is shown in Table 1 below.
Particle size distribution.

[0010]

[Table 1]

The method in which the granular static crushing agent filled in the container absorbs water comprises forming the container itself from an impermeable material,
The openings at both ends are covered with a net formed of a mesh that does not allow the granules to fall off, and water is absorbed through the net. The stable liquid that the static crushing agent absorbs is injected into the pile hole in order to prevent collapse of the peripheral wall of the pile hole at the time of excavation of the pile hole, and for example, CMC or a dispersant is added to the bentonite solution or the bentonite solution. Things and the like are used.

As a means for the static crushing agent to absorb the stabilizing liquid in the pile hole, when the stabilizing liquid is sufficiently filled in the pile hole, the container is inserted when the reinforcing cage is inserted into the pile hole. If the stabilizing liquid is not sufficiently filled by immersing it in the stabilizing liquid, or if the stabilizing liquid is not sufficiently filled, raise the water level of the stabilizing liquid when placing concrete, and then immerse the container in the stabilizing liquid to statically Perform water absorption of crushing agent. The optimum hydration condition of the static crushing agent can be adjusted by adjusting the time of immersion in the stabilizing solution.

[Pile head treatment method using the static crushing agent of the present invention] Next, a method of implementing the pile head treatment method using the static crushing agent according to the present invention will be described with reference to FIG.

First, a pile hole is excavated in the presence of a stabilizing solution.
Then, the main bar margin cutting material is attached to the reinforcing bar main bar (step 10).
1). Next, the container is filled with the granulated static crushed material, and the container is attached to a reinforced cage (step 102). Insert and sink. When the container is immersed in the stabilizing liquid, the stabilizing liquid enters the container from the nets at both ends of the container, and the penetrating stable liquid sufficiently wraps the granular static crushed material, and enters the inside from the outer periphery of the static crushed material. Water is absorbed (step 103). Thereafter, the concrete is poured up to above the crushing plan line while replacing the concrete with the stabilizing liquid (step 104). After the casting is completed, cure until the strength of concrete is developed. At the same time, hydration and expansion of the statically crushed material is aimed at (step 105). Then, after the curing of the concrete is completed, a crack is generated on the crushing plan line after the expansion pressure of the static crushing agent is developed, the excess concrete portion is removed, and the processing of the pile head is completed (step 10).
6).

When the treatment method of the present invention is compared with the conventional method shown in FIG. 2, the water of the static crushing agent is measured, the water is kneaded with the crushing agent, and the container previously attached to the reinforcing rod cage. The operation of filling the slurry (step 107) can be omitted in the case of the present invention.

[0016]

According to the above construction, the container with the static crushing agent according to the present invention is a cylindrical impervious container filled with the static crushing agent and having both ends opened, so that the pile head of the cast-in-place pile is formed. At the time of treatment, it is attached to a predetermined position of a reinforcing rod cage along the crushing plan line, and when immersed in a highly viscous bentonite solution or a stable solution obtained by adding a CMC or a dispersant to a bentonite solution, from both ends opened. Infiltrate a highly viscous stabilizing liquid, sufficiently wrap the static crushing agent with the stabilizing liquid, express sufficient hydration expansion pressure to the static crushing agent after placing concrete, and make large cracks along the crushing plan line. And generate
To realize a container with a static crushing agent for pile head treatment of cast-in-place piles that is easy to handle and has good workability.

The static crushing agent filled in the container has a particle size of 1 to 2 mm of 15 to 20% by weight and a particle size of 2 to 4 mm of 5 to 20% by weight.
By being granulated into granules having a particle size distribution of 5 to 60% by weight and a particle size of 4 to 5 mm being 35 to 20% by weight,
When used for pile head treatment of cast-in-place piles, when immersed in a highly viscous bentonite solution or a stable solution obtained by adding a CMC or a dispersant to a bentonite solution, the highly viscous stable solution sufficiently wraps each granule. The moisture in the stable liquid is allowed to penetrate from the granule surface to the inside of the granule, and after an appropriate time, according to the concrete strength, the hydration expansion pressure is properly expressed,
A crack of about several centimeters is generated along the crushing plan line, and the excess concrete can be removed.

[0018]

EXAMPLE CAB (a product of Sumitomo Cement Co., Ltd.), which is a kind of static crushing agent, was formed into granules, and as shown in FIG.
A flat spiral sheath tube 1 (maximum diameter 45 mm, length 50 cm) was filled. Then, both ends of the spiral sheath tube 1 were closed with a net 4, and a plurality of them were arranged along the reinforcing bar 3 on the planned cutting line 2 of the cast-in-place concrete pile head (diameter 1 m), and attached with a binding wire. . Next, the steel cage 3 was inserted into the pile hole, the spiral sheath tube 1 was submerged in the stabilizing solution, and concrete was poured. And 1
When digging was performed after the elapse of 0 days, generation of a crack having a width of 1 to 2 cm was recognized along the planned cutting line 2.

[0019]

As described above, according to the container containing a static crushing agent of the present invention, a cylindrical impervious material filled with a static crushing agent having a predetermined particle size distribution and opened at both ends is provided. By using a container, at the time of pile head treatment of the cast-in-place pile, it is attached to a predetermined position of the reinforcing rod cage along the crushing plan line, and is a highly viscous bentonite solution or a stable liquid obtained by adding CMC or a dispersant to the bentonite solution. When immersed in concrete, a highly viscous stabilizing liquid can penetrate from both open ends, and the stabilizing liquid can sufficiently wrap the static crushing agent. A large crack can be generated along the fracture planning line, which is easy to handle and has good workability. it can.

The static crushing agent filled in the container has a particle size of 1 to 2 mm of 15 to 20% by weight and a particle size of 2 to 4 mm of 5 to 20% by weight.
By being granulated into granules having a particle size distribution of 5 to 60% by weight and a particle size of 4 to 5 mm being 35 to 20% by weight,
When used for pile head treatment of cast-in-place piles, CM is used for highly viscous bentonite solution or bentonite solution used during excavation.
When immersed in a stable liquid to which C or a dispersant has been added, a highly viscous stable liquid can sufficiently wrap each granule,
The moisture in the stable liquid permeates from the granule surface into the inside of the granule, improves water absorption and hydration reactivity, and after a suitable time, the hydration expansion pressure can be properly developed according to the concrete strength. It is possible to generate a crack of about several centimeters along the crushing plan line, so that excess concrete can be easily removed.

[0021] For this reason, it is possible to omit the measurement and the kneading operation of the kneading water as the operation before filling the container with the required static crushing agent, thereby simplifying and speeding up the operation. In addition to this, the work of removing the excess concrete can be easily performed, and the time and cost can be reduced in the pile head treatment of the cast-in-place pile.

[Brief description of the drawings]

FIG. 1 is a flowchart showing working steps of a pile head treatment method using a stabilizing solution according to the present invention.

FIG. 2 is a flowchart showing a work process of a conventional example.

FIG. 3 is an explanatory perspective view showing a state in which a spiral sheath tube is attached to a reinforcing bar.

[Description of sign]

 1 Spiral sheath tube 2 Cutting line 3 Reinforcing cage

Claims (1)

(57) [Claims] A particle size of 1 to 2 mm is 15 to 20% by weight, a particle size of 2 to 4 mm is 55 to 60% by weight, and a particle size of 4 to 5 mm is 3%.
A container containing a static crushing agent, which is a cylindrical impervious container filled with a static crushing agent granulated into granules having a particle size distribution of 5 to 20% by weight and having both ends opened. .